Detection and Characterization Algorithm of Swept Continuous Wave Interference for Safe GBAS Operation

Abstract

In this paper, an adaptive lattice IIR notch filter [1] is employed to track single-tone continuous wave and swept continuous wave interference signals, and an interference detection method is proposed. The performance of the interference detection algorithm is analyzed using software GPS and interference simulator data. Furthermore, this paper presents interference source characterization algorithm using multiple ground stations interference detection and power estimation results. The estimation results from each ground station include the type of interference (single-tone or swept), and estimated power. They will be combined to obtain more information of the interference sources including more precise frequency estimates, and the location of interference. The estimated interference powers from each ground station will be used to build weighting factors to estimate the type of the interference more precisely. If one ground stations estimated power of the interference is greater than the power of others, the weight factor will be increased, and its result is used to decide the types of interference. The performance of interference detection and power estimation algorithm is simulated for scenarios of GPS signal in the presence of single-tone continuous wave interference and swept continuous wave interference.